Antimicrobial resistance and genotyping of Staphylococcus aureus obtained from food animals in Sichuan Province, China

Abstract

Background Staphylococcus aureus (S. aureus), especially methicillin-resistant Staphylococcus aureus (MRSA), is considered a common zoonotic pathogen, causing severe infections. The objective of this study was to investigate the antimicrobial susceptibility, resistance genes and molecular epidemiology among MRSA and methicillin-susceptible Staphylococcus aureus (MSSA) isolated from food animals in Sichuan Province, China. Methods This study was conducted on 236 S. aureus isolates. All isolates were subjected to antimicrobial susceptibility testing by using a standard microbroth dilution method. The Polymerase Chain Reaction (PCR) was performed to identify genes encoding the β-lactams resistance (blaZ, mecA), macrolides (ermA, ermB, ermC) and aminoglycosides (aacA-aphD). The molecular structures and genomic relatedness of MRSA isolates were determined by staphylococcal chromosome cassette mec (SCCmec) typing and pulsed-field gel electrophoresis (PFGE), respectively. Results Among 236 isolates, 24 (10.17 %) were recognized as MRSA. MRSA isolates showed different resistance rates to 11 antimicrobials ranging from 33.33 to 100 %, while for MSSA isolates the rates varied from 8.02 to 91.51 %. Multi-drug resistance phenotype was found in all MRSA isolates. The ermC gene encoding macrolides-lincosamides-streptogramin B was the most prevalent gene detected in 87.29 % of the S. aureus isolates, followed by ermB (83.05 %), blaZ (63.98 %), aacA-aphD (44.07 %), ermA (11.44 %) and mecA (11.02 %) genes. The prevalence of resistance genes in MRSA isolates was significantly higher than that of MSSA. Regarding the molecular morphology, SCCmec III (12/24, 50 %) was the most common SCCmec type. Furthermore, the PFGE typing showed that 24 MRSA were divided into 15 cluster groups (A to O), the major pulsotype J encompassed 25 % of MRSA isolates. Conclusions The S. aureus isolates from food animals in Sichuan province of China have severe antimicrobials resistance with various resistance genes, especially MRSA isolates. Additionally, the genetic pool of MRSA isolates is diverse and complex, and further investigation is necessary.

Antibiotic Susceptibility Profiling of Human Pathogenic Staphylococcus aureus Strains Using Whole Genome Sequencing and Genome-Scale Annotation Approaches

“…A gene encoding macrolides–lincosamides–streptogramin resistance ( ermC ) and rep10 were identified in plasmid pE5 circulating in three isolates: S1, S14, and S23. These results indicate that these isolates have acquired these genes from others via plasmids, which is in accordance with previous studies [ 58 , 59 ]. Horizontal transfer of the ermC gene in a small plasmid was commonly documented in animal and human staphylococcal species [ 59 ].…”

Identification of Antibiotic Resistance Pattern and Antibiotic Resistance Gene of Staphylococcus aureus from Broiler Chicken Farm in Sukabumi and Cianjur Regency, West Java Province, Indonesia

“…The ermB gene in this research is comparable to a study reported in Isfahan, Iran, where only 22.2% of ermB genes were detected [48], while our result was lower than that found in Sichuan Province, China, food animals [49]. In addition to ermA, ermC, and ermF, ermB is the most prominent gene in staphylococci that significantly contributes to macrolide, lincosamide, and streptogramin B antibiotics [50].…”

Tedizolid versus linezolid activity against Staphylococcus aureus clinical isolates

“…In recent decades, the unwise use of antibiotics culminated into spread of resistant S. aureus isolates, especially MRSA. Worryingly, isolates with diminished susceptibility to vancomycin have been described worldwide and are associated with unfavorable prognosis 20 . Though both linezolid and tedizolid were approved for management of S. aureus infections worldwide, no much data have been published from Egypt in this context.…”